The bomber attacked the headquarters of a Kurdish political party in the ethnically mixed Diyala province, according to reports. Most of those hurt were members of the Kurdish security forces who were guarding the office of the Patriotic Union of Kurdistan (PUK).

“A suicide bomber parked a car packed with explosives near the PUK headquarters and when it went off, he managed to sneak into the building and detonated his vest,” said Khorsheed Ahmed, the chairman of Jalawla city council.

The blast on Sunday followed a dozen bombings in Iraq on Saturday that killed more than 60 people. Militants stormed a university campus in the west of the country, according to the Reuters news agency, which cited security and medical sources.

In total, there were a dozen blasts in mainly Shi’ite districts of the capital Baghdad, the deadliest of which occurred in Bayaa, where a car bomb left 23 people dead, many of them young men playing billiards.

“I was about to close my shop when I heard a huge explosion on the main commercial street,” said Kareem Abdulla, whose legs were still shaking from the shock. “I saw many cars set ablaze as well as shops”, he told Reuters.

Other bombs went off near a cinema, a popular juice shop and a Shi’ite mosque.

‘Security will get worse’

No group has yet claimed responsibility for any of the bombings, but the Shi’ite community is a frequent target for Sunni Islamist insurgents who have been regaining ground and momentum in Iraq over the past year.

Since Thursday June 5, militants have seized parts of Ramadi and Falluja, the two main cities in the mainly Sunni Anbar province. And, on Saturday, they took control of the campus of Anbar University in Ramadi.

The latest attack took place in the town of Jalawla, 70 miles northeast of Baghdad.

A member of the security and defence committee in the Iraqi parliament said the insurgency could not be quelled by force alone because the root cause was political. Critics of Iraq’s Shi’ite-led government say its treatment of the once-dominant Sunni minority is the main driver of the insurgency.

“The Iraqi government now relies on using force to solve things, that is why security will get worse,” said Shwan Mohammed Taha, predicting that violence could spread to other Sunni-dominated provinces such as Diyala.

“This is not only deterioration, it is a failure to manage the security file.”

Parts of Ramadi have been held by anti-government tribesmen and insurgents since the start of the year. Overnight, gunmen fought their way past guards into the university, planting bombs.

They eventually allowed students and teaching staff to leave, but remained in control of the campus late on Saturday, exchanging fire with security forces.

A professor trapped inside the physics department told Reuters some staff who live outside Ramadi had been spending the night at the university because it was the exam period.

“We heard intense gunfire at about 4 a.m. We thought it was the security forces coming to protect us but were surprised to see they were gunmen,” he said, adding: “they forced us to go inside the rooms, and now we cannot leave.”